It was common to use white or black targets in order to measure a vision or a field of view in the past (for example, patent related document 1 shown below). But, we are surrounded by many chromatically colored materials, and in fact, there are few white or black materials in our circumstances. Then, recently, measurement of vision or field of view adding influences of colors is increasingly attracting attention, but not measurement with white or black targets. And, various methods are proposed (for example, see patent related documents 2 and 3 shown below).